Re: [Approach #2] [RFC][PATCH] Remove cgroup member from structpage

From: KAMEZAWA Hiroyuki
Date: Wed Sep 10 2008 - 06:59:17 EST


On Thu, 11 Sep 2008 06:44:37 +1000
Nick Piggin <nickpiggin@xxxxxxxxxxxx> wrote:

> On Wednesday 10 September 2008 11:49, KAMEZAWA Hiroyuki wrote:
> > On Tue, 9 Sep 2008 18:20:48 -0700
> >
> > Balbir Singh <balbir@xxxxxxxxxxxxxxxxxx> wrote:
> > > * KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> [2008-09-09
> > > 21:30:12]: OK, here is approach #2, it works for me and gives me really
> > > good performance (surpassing even the current memory controller). I am
> > > seeing almost a 7% increase
> >
> > This number is from pre-allcation, maybe.
> > We really do alloc-at-boot all page_cgroup ? This seems a big change.
>
> It seems really nice to me -- we get the best of both worlds, less overhead
> for those who don't enable the memory controller, and even better
> performance for those who do.

No trobles for me for allocating-all-at-boot policy.
My small concern is
- wasting page_cgroup for hugepage area.
- memory hotplug

>
> Are you expecting many users to want to turn this on and off at runtime?
> I wouldn't expect so, but I don't know enough about them.
>
There is no runtime switch. only at boot.

Thanks,
-Kame

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